A general cylinder device in the prior art is constituted so that a piston is slidably accommodated in a cylinder chamber within a cylinder tube, while a piston rod is connected to the piston, and a working fluid such as oil or air is introduced into one room of the cylinder chamber defined by said piston so that a pressure is applied to one surface of the piston, and similarly to this, the working fluid is introduced into the other room of the cylinder chamber, or an exterior mechanical force is actuated thereon, whereby the piston and accordingly the piston rod is moved in a reciprocating motion according to the relation of both forces.
However, in the above-mentioned prior art cylinder device, there is a problem that if an attempt is made to lengthen the stroke of the cylinder device, the cylinder tube also becomes longer in length in proportion to the lengthened stroke, thus making the production of a smaller-sized cylinder device difficult.
That is, if an attempt is made to obtain a sufficient stroke by using the above-described cylinder device for, for example, a double housing balancing device which supports the cross beam of a double housing type large machine tool, the cylinder devices protrude from the columns of the machine tool toward the ceiling at the right and left positions. Conversely, if the cylinder device is short in stroke, the total length thereof becomes large when it retracts, thus resulting in a large distance between the cross beam and the bed of the machine tool. In short, under the existing circumstances, even if the provision of a large machine tool is planned for a factory, the restriction in the height of the structure of the factory limits the intended range of machining a work, and furthermore, the cylinder devices protruding from the columns obstruct the travelling of a crane when the devices are in operation after being installed in the factory.